Innervation of the heart
Citation, DOI, disclosures and article data
At the time the article was created Henry Knipe had no recorded disclosures.View Henry Knipe's current disclosures
The extrinsic supply is from parasympathetic (from the vagus nerve) and sympathetic nerves from both the superficial and deep cardiac plexuses, which provide post-ganglionic fibers to the sinoatrial (SA) and atrioventricular (AV) nodes, as well as other parts of the cardiac conduction system.
The cardiac conduction system represents the intrinsic component and is composed of (in order of depolarization):
right and left bundle branches
Cardiac myocyte conduction spreads through the heart from myocyte-to-myocyte starting at the SA (pacing) node and then via other parts of the cardiac conduction system in turn as outlined above.
Each part of the cardiac conduction system has its own intrinsic pacemaker, which means that if a higher pacing center (e.g. SA node) is damaged and stops functioning a lower pacing center (e.g AV node) can take over.